Alloy



v pressures and velocities of rim Patented July 26, 1932 CEABLES I. HAMMOND, OF NEW BEPEATING ARMS COMPANY,

HAVEN, CONNECTICUT, ASSIGNOR TO WINCHESTER OF NEW HAVEN, CONNECTICUT, A CORPORATION OF ALLOY MARYLAND In Drawing. Application filed May 20, This invention relates to an alloy and more particularly to an alloy adapted for use in the manufacture of cartridge cases for small arms ammunition.

Heretofore cart-ridge cases have been made of copper or gilding metal. Recently the fire ammunition have been increased to make the ammunition more suitable for rim fire target shooting. To obtain the increase in pressures and veloci; ties, it is necessary to employ a more powerful charge of propellant powder. This has led to the fact that the copper and gilding metal heretofore employed in the construction of cartridge cases do not have the inherent strength necessary to permit them to be used with the more powerful loads.

A suitable substitute must not only possess the necessary strength to withstand the increased load but must-be workable to permit the formation of the cartridge cases in the usual manner and must be incapable of amalgamatin with free mercury. It has been propose to form the cases of brass and eliminate mercury fulmi'nate from the priming mixture. While priming mixtures' containing no mercury fulminate are known and have been used to some extent, such nonmercuric primingmixtures have not proved suitable for all purposes and accordingly the proposal referred to above has not solved the question.

I have found that a copper alloy containing silicon, manganese and zinc has the additional strength necessary to withstand the increased pressure to which cartridge cases are submitted in modern ammunition, can be easily worked to permit the manufacture of cartridge cases by and will not amalgamate with any free mercury that maybe present in the mercury fulminate of the priming mixture.

I am aware of the prior use of manganese and silicon in a copper alloy to produce an acid resistant material. ever, that by adding zinc to the alloy heretofore used and reducing the amount of silicon and managanese the tensile strength and workability of the alloy is increased to a I have found, howthe methods now employed 1932. Serial no. 612,639.

marked extent. I therefore propose to use the ingredients in substantially the following proportions:

Silicon 0.15 7 to 1.007.preferably 0.697

Manganese 0.17 to 1.00'7:-preferably 0.24%

Zinc 143.01% to 6.00%.preferably 5.00%

The metals may be alloyed in any suitable way by melting the proper proportions together and casting into ingots. The cast. ingots are mechanically worked and cold rolled into thin sheet or strip metal to further increase the stren th and d d f difliculties in ammumtlon manufacture due to g ma 8 Tea y or Sub sequent operations of cartridge manufacture. The resulting alloy is readily workable permitting it to be used in the manufacture of cartridge cases and also possesses high tenslle strength permitting its use with modern ammunition.

The alloy may not only be used in the manufacture of cartridge cases but also in the manufacture of other products in which the properties referred to above are desired.

I claim:

1. An alloy comprising the following ingredients in substantially the following proportions: 1

Silicon 0. 15% to 1. 00%

Manganese 0. 17% to 1. 00% inc 4. 0% to 6. 00%

Copper alance.

2. An alloy comprising the following ingredients in substantially the following proportions:

Silicon 0. 69% Manganese 0. 24% Zinc 5. 00% Copper Balance.

In testimony whereof I aflix my CHARLES F. HAMMOND signature. 

